Power system



Sept. '9 1924. 1,508,364

- 7 J. D. HILLIARD POWER SYSTEM Filed Sept. 18, 1923 Inventor- I poi-m D. Hilliard,

His Attorney.

Patented Sept. 9, 1924.

UNITED STATES PATENT OFF 1,508,364 ice.

JOHN D. HILLIARD, OF SOHENECTADY, NEW YORK. ASSIGNOR TO GENERAL ELECTRIC COMPANY. A CORPORATION OF NEW YORK.

POWER SYSTEM.

Application filed September 18, 1923. Serial No. 663.510.

To. all whom it may concern:

1 Be it known that I. JCI-IN D. HILLIARD, a citizen of the United States, residing at Schenectady. in the county of Schenectady, State of. New 'York, have invented certain new and useful Improvements in Power Systems, of which the following is a specification.

My invention relates to electric power systerns wherein line conductors are provided failures are avoided by the use of a condu'ctor having two conducting elements in sulated from eachother and normally connected in parallel but arranged tobe disconnected at one end in response to the accumulation of sleet on an object in proximity to the line and to be automatically connected to a source of current for heating the loop thus formed. For this purpose use may be made of a cable with a conductingcore in- I sulated from the outer layers of wire by a layer of paper or the like impregnated by an insulating material. such as bitumen. which will not deteriorate when exposed to the weather, the entire cable being run through an impregnating bath to prevent the penetration of moisture between the strands if desired. 1

My invention will be better understood from the following description when considered inconne'ction with the accompanying drawing and its scope will be pointed out by the appended claims.

Referring now to the drawing. Fig. 1

shows the application of my invention to a span or section of transmission line. Fig. 2 shows a detail of the apparatus illustrated by Fig. 1, and Fig. 3 shows a modified form of my invention.

Fig. 1 shows a transmission line 1 comprising conductors 2 and 3 insulated from each other throughout the span and perma nently connected together at one end of the span, as at the left hand end for example. Under normal conditions the conductors 2 and 3 are also connected to each other at the right hand end of the spanlby means of a switch blade 4: pivoted at the point 5 and arranged to be opened in response to the accumulation of sleet on a grid member 6 fixed to a lever 7 pivoted at the point 8 and mechanically connected to the blade 4 through a rod 9. At the opposite end of the lever 7 a counter weight 10 is provided for the purpose of maintaining the blade 4 in contact with the terminals 11 and 12. A current transformer 13 has its secondary winding 14 connected between the conductors 2 and 3 and its primary winding 15 connected between the conductor 3 and an adjacent span 16 of the transmission line. lVhen the switch blade 4 is in closed p0sition. current may be transmitted through the conductors 2 and 3 in parallel and the primary winding of the transformer 13 is short-circuited by the conductor: 17. Upon movement of the switch blade 1 to its open position the conductor 2 is disconnected from the span 16 and the line current is carried by the conductor 3 connected in series with the primary winding 15 of the transformer 13, the secondary winding 14 will of course depend on the value of the line current and the transformation ratio of the current transformer 13. The member 6, as indicated by Fig. 2. may oonsist of a frame 18 upon which is mounted a plurality of cross wires 19 for the purpose of facilitating the accumulation of sleet. \Vhile the member 6 is shown as horizontally arranged under normal conditions, it obviously may be made in the form of a sheet or slab and tilted for the purpose of preventing an accumulation of snow thereon.

Fig. 3 shows a modified form of the in' vention in which means are provided for melting an accumulation of snow or sleet off the grid member at the same time that heating current is caused to circulate through the conductors of the line. This modification comprises a lever 20 pivoted at the point 21 and having fixed to one of its ends an insulation member 22 around which are wound heating coils 23 connected means of an insulator :29.

and- 31. An accumulation of snow or sleet on the grid member causes the'blade 20 to move downwardly out of engagement with contact members 30 and 31 and into engage- -ment with contact 24 thereby connecting the primary winding 15v and the heating coils in series with the line; Melting of the sleet or snow on the grid permits the switchv blade 20to automatically return to its normal'position. The'switch isthus repeatedly operated as often as necessary and is eventually left in its normal operating position. It is evident that the heating of the mainconductor should be greater than the heating of the resistance grid in order to insure that'the main conductor is free from depositbefore the switch returns to its normalpositionl' i V While I have described the principle of my invention, together with the apparatus which I now-consider to represent the best embodiment thereof. I desire to have it ungderstoodthat the apparatusis only illustrative and that the invention can be carried out by other means.

What I claim as new and desire to secure by Letters Patent ofv the United States is,

1. An electric power system wherein conductors arranged to transmit current from one location to another are exposed to the Weather, characterized by the fact that means responsive't'o an accumulation of sleet are provided for causing said conductors to be heated whereby said conductors are protected from injury-due to an accumulation of sleet upon'them. Y

a 2, An electric power system comprising a conductor-made of two conductive elements insulated from each'other through- V out their length and permanently. connected together at one end, a switch for interconnectlng said conductors at the other end,

and means responsive to an accumulation of sleet for opening saidswitch.

Bi An electric power system comprising a means are arranged to prevent conductor made of ,two conductive elements insulated from each otherlthroughout their length, a transformer having its secondary windings connected between said elements, means for connecting said elements in panallel including a switch arranged to connect said elements together at one end and to short circuit the primary winding of said transformer, and means responsive to an accumulation of sleet for opening said switch to disconnect said elements from each other at one end' and to connect the primary winding of said transformer in series with-one of said elements. i a

4. The method of protecting a transmission line from injury due'to an accumulation of sleet which comprises sending a heating current therethrough in response to theaccumulation of sleet on an object located in proximity to said line.

5. A system of the class'described comprising a conductor made of two conductive elements insulated-from each other throughout their length, a current transformer having its secondary winding connected in series with said elements, means for connecting said elements in parallel includingza switch' arranged to interconnect said elements at a point near said transformer, and toshort circult the prlmary winding of said transformer, and meansresponsive to an accumulation of sleet for opening said switch to disconnect said elements at the end adjacent the transformer and to connect said primary winding in seriesiwithone of said elements.

6. A system .of the class described wherein conductors arranged to transmit 1 current from one location to another are exposed to the weather; characterized by the factthat:

means responsive to an accumlation of sleet are provided for causing said conductors to be heated and bythe further' fact that said an aceume1ation of snow upon itself. i '7, A system of the class described compris in a conductor made of two conductive elements insulated from each other throughout their length and arranged to be connected inparallel, a switch for'interconnecting said conductors at one end, and means responsive to an' accumulation of sleet for opening said switch, said means comprising a'conductor" connected in series'with saidcond-uctive olements when said switch is' closed; i In witness whereof I hereuntofset my hand 1 this 17th day'of September, 1923.

h J OHN"D.'HILLIARD. 

